Frontal Polymerization with Thiol−Ene Systems

Frontal polymerization in multifunctional thiol-ene systems was demonstrated. For an ene that could not undergo free-radical-chain propagation, the front velocity and front temperature were a maximum at the stoichiometric ratio of the thiol and ene. For a system like HDDA, which can homopolymerize as well as copolymerize with the thiol, the addition of even a small amount of thiol increased the front velocity by as much as 80% by reducing oxygen inhibition.